1. Technical Field
The present invention relates generally to an improved data processing system and in particular to a method and apparatus for processing data. Still more particularly, the present invention relates to a method, apparatus, and computer instructions for system monitoring.
2. Description of Related Art
In producing processor chips, chip makers gauge success based on yields as much as any other factor. A company that is able to execute and consistently deliver high yields will generally be able to meet customer demands. This situation is particularly true for cutting edge semiconductor fabrication processes in which chips command higher prices. With respect to yields, chips containing two or more processor cores may often be discarded because one of those cores do not meet the performance or testing parameters needed to identify the chip as a good chip. Testing of chips is performed for parametric faults and random defects. The manufacturing test is performed to see whether the manufactured chip meets the specifications for the particular type of processor.
These tests typically test every device on the chip. Tests that may be performed include functional and structural tests. A functional test tests the chip function in normal operation while a structural test specifically focuses on manufacturing defects that might cause the chip to behave differently from normal operations. Tests that may be performed on a core include, for example, a test pattern source and sync. The source generates test stimuli for the embedded core and the sync compares the response responses to the expected responses.
Some of the tests involve a burden or stress test. Such a process subjects a chip to high temperature and over voltage supply while running production tests. In attempting to increase the yield, one mechanism used is to steadily refine and optimize the process for manufacturing the chips. Another effort used in increasing yields is to identifying the optimal numbers of chips on a wafer.
Even with all the current processes and techniques for increasing wafer yields, a large number of chips are wasted or sold with fewer cores because one or more processor cores do not meet the specifications. Such a situation may occur with super-scaler processors, which often have multiple copies of execution units. If execution units are defective, the processor cores may still function, but not for the purpose of super-scaler processing. Therefore, it would be advantageous to have an improved method, apparatus, and computer instructions for reducing the number of chips that are discarded due to defects in a processor core.